1. Field of the Invention
The present invention relates to a controller for use with an articulating arm used in non-invasive medical procedures.
2. Background of the Present Invention
Presently there are numerous methods and devices used by medical professionals to keep a medical device in close proximity to a patient during a procedure. These devices are largely deployed by hand, positioned by hand and rely on tension mechanisms to maintain their position relative to the patient.
Among the prior art, there are few articulating arms used in the medical industry for maintaining the precise location of an effector at the tip of an articulating arm to a patient. Articulating arms are used in various other industries such as manufacturing, machine tooling and robotic applications. Applications in manufacturing for heavy lifting and repetitive tasks may use robotic arms or load balancing arms. Robotic arms are capable of performing repetitive tasks and tasks involving heavy lifting so that a user is not burdened with performing these operations. Robotic arms are programmable so they can move autonomously between two or more positions. Generally a user programs the arm to move between a first position and any number of secondary positions so the robotic arm can carry out numerous tasks. Robotic arms are used on assembly lines to move parts from supply areas to assembly areas, and to secure parts to each other in assemblies, such as in the production of automobiles, circuit boards and other mass produced items. Robotic arms generally use encoders or other position sensors so the machine controlling the arm, be it a variable stage computer program or a simple electronic controller, know where the robotic arm is and how much it needs to be moved to perform its task. While robotic arms are enormously useful devices, they are primarily used in assembly and routine repetitive tasks. There are few robotic arms having the delicate and intricate movement ability as is demanded and required in medical procedures.
U.S. Pat. No. 4,291,578 describes an articulating arm for use with an ultrasound probe. The probe is used to guide an invasive insertion (needle or catheter) and the arm has a spring responsiveness giving it a light touch for easy use. The arm is attached to a vertical support extending from a pivoting and weighted base incorporated into a bed. The reach of the arm is restricted to the top half (torso) of the patient body.
U.S. Pat. No. 5,807,377 described an endoscopic robotic device for use in a minimally invasive surgical procedure. The manipulation of the medical device at the end of the manipulator arm is achieved by handles offering high dexterity and low friction. However such manipulator arms are not suited for carrying or maneuvering heavy objects.
U.S. Pat. No. 6,488,030 describes an apparatus for use in a medical biopsy procedure. An articulating arm is used having a stage or platform at the end that includes a micro-advancement control for ultra fine advancement of a biopsy probe. The arm is positioned manually in relation to the patient and the platform on the articulating arm is designed for use with a minimally invasive procedure.
U.S. application Ser. No. 10/751,344 describes an articulating arm in either a load balancing or powered robotic mode. The arm is used to maneuver a therapy device into position over a patient. The movement of the arm is guided either by direct manipulation of a human being, or by a computer. This application is herein incorporated by reference.
Various instruments designed for minimally invasive procedures also utilize robotic or semi-autonomous features. However these devices are not suited for noninvasive procedures.
Generally load balancing arms enable a user to grab and move loads directly in a natural manner. The weight of the load is compensated for so the user feels the load is within his or her natural lifting capacity. The load balancing arm provides the advantage of allowing a human user to guide the arm to move objects in a natural manner. That is to say, load balancing arms are designed primarily to assist a user in moving heavy objects by supplementing a person's lifting ability, and moving in the same motions a human being normally makes. The closer the load balancing arm lifting force is to the weight of the load, the less force the user is required to exert on the arm to move the load. Because load balancing arms are generally assisting devices that rely on a user to guide and control their movement, there is no need for any sort of position control or tracking of the movement of a load balancing arm. Some arms used for providing industrial measurement of solid objects provide limited forms of counter weighting and position encoders, however these devices are not designed for carrying any sort of substantial loads, nor do they provide for any form of adaptive positioning.
Thus there are no robotic arms or load balancing arms that provide a combination of; feather touch, location controller and location awareness in real time, and with the ability and design for use in a medical environment.
Thus there remains a need in the art for a device that can provide a full range of motion over a patient body, allowing a physician or user to place an effector at the end of an articulating arm, and to control its precise relational position with the patient, and control the position either manually or automatically.
There is also a need for a device that can provide adaptive positioning and match the regular movement of a patient body (e.g. breathing) so that the effector of the articulating arm does not change position relative to the patient during the course of the procedure unless specifically intended to do so by the physician.
There is further a need for an articulating arm for medical procedures having a load balancing mechanism for procedures of extended duration, or procedures requiring an effector to be properly positioned and provide a hands free environment for the user to do something else.
There is still further a need for a closed loop controller for the precise control of the effector in relationship to both the patient and the external environment. At least one of these needs is addressed by the following disclosure.